package com.yupi.springbootinit.utils;

import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.io.FileUtil;
import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.support.ExcelTypeEnum;
import com.yupi.springbootinit.common.ErrorCode;
import com.yupi.springbootinit.exception.ThrowUtils;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.ObjectUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.util.ResourceUtils;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * Excel相关工具类
 */
@Slf4j
public class ExcelUtils {

    /**
     * Excel 转 csv
     * @param multipartFile
     * @return
     */
    public static String excelToCsv(MultipartFile multipartFile){
        // File file = null;
        // try {
        //     file = ResourceUtils.getFile("classpath:网站数据.xlsx");
        // } catch (FileNotFoundException e) {
        //     e.printStackTrace();
        // }
        // 读取数据
        List<Map<Integer, String>> list = null;
        try {
            list = EasyExcel.read(multipartFile.getInputStream())
                    .excelType(ExcelTypeEnum.XLSX)
                    .sheet()
                    .headRowNumber(0)
                    .doReadSync();
        } catch (IOException e) {
            log.error("表格转csv错误", e);
        }

        if (CollUtil.isEmpty(list)) return "";
        // 转换为csv
        StringBuilder stringBuilder = new StringBuilder();
        // 读取表头
        LinkedHashMap<Integer, String> hashMap = (LinkedHashMap) list.get(0);
        // 过滤掉为null的
        List<String> headerList = hashMap.values().stream().filter(ObjectUtils::isNotEmpty).collect(Collectors.toList());
        stringBuilder.append(StringUtils.join(headerList, ",")).append("\n");

        for (int i = 1; i < list.size(); i++) {
            LinkedHashMap<Integer, String> dataMap = (LinkedHashMap) list.get(i);
            List<String> dataList = dataMap.values().stream().filter(ObjectUtils::isNotEmpty).collect(Collectors.toList());
            stringBuilder.append(StringUtils.join(dataList, ",")).append("\n");
        }
        return stringBuilder.toString();
    }
    /**
     * 检查文件
     *
     * @param file 文件
     */
    public static void checkExcelFile(MultipartFile file) {
        long size = file.getSize();
        String originalFilename = file.getOriginalFilename();
        // 校验文件大小
        final long ONE_MB = 1024 * 1024L;
        ThrowUtils.throwIf(size > ONE_MB, ErrorCode.PARAMS_ERROR, "文件超过 1M");
        // 校验文件后缀 aaa.png
        String suffix = FileUtil.getSuffix(originalFilename);
        final List<String> validFileSuffixList = Arrays.asList("xlsx", "xls");
        ThrowUtils.throwIf(!validFileSuffixList.contains(suffix), ErrorCode.PARAMS_ERROR, "文件后缀非法");
    }
    //
    // public static void main(String[] args) {
    //     excelToCsv(null);
    // }
}
